Lettherebelight
If x and y are positive, is x < y?
(1) \(\sqrt{x} < \sqrt{y}\)
(2) \((x-3)^2 < (y-3)^2\)
Use the number line approach for stmnt 2 to avoid writing anything.
(1) \(\sqrt{x} < \sqrt{y}\)
Squaring both sides because principal square roots are always positive, we get
x < y
Sufficient.
(2) \((x-3)^2 < (y-3)^2\)
Since both sides are squares so positive, we can take the square root to get
|x - 3| < |y - 3|
(Check this post if you are not sure how:
https://anaprep.com/algebra-squares-and-square-roots/ )
Distance of x from 3 < Distance of y from 3
So imagine the number line. Either is possible.
______ 1 (= y)_________ 2 (=x) _________ 3 ________ 4 (=x) _______ 5 (= y) _______
x has a smaller range around 3 than y, but in some cases x < y (e.g. x = 2 and y = 5) while in other cases y < x (e.g. x = 2, y = 1)
Not Sufficient
Answer (A)
Check: How to use number line on GMAT:
https://youtu.be/3gxVx3Y9xJA